The incident has once again raised questions over whether concealed weapons do more harm than good.

Concealed weapon ownership has skyrocketed in recent years in the United States due in part to successive mass shootings. A survey released in December found two-thirds of Americans consider mass shootings a ‘critical’ issue for the country, and the percentage of Americans who believe owning a gun will protect them has risen to unprecedented levels.

Yet people with concealed-carry permits are more likely to commit mass shootings than to stop them, according to The Washington Post’sChristopher Ingraham. He found concealed-carry permit-holders have committed at least 29 mass shootings since 2007, compared with roughly eight known cases of permit-holders using their weapons to stop such mass shootings.